Pre-fabrication of components of a structure is preferable practice for construction economy by reducing construction time thus allowing for early occupancy and the early return of investment capital. Pre-fabrication applies to exterior façade facing panels of a structure. Facing panels may be made of any applicable single or multiple materials, of any thickness or composition, and in any combination thereof, and may be attached to the same mullion, may have a frame exposed at the outside and may be monolithically frameless.
Construction economy is achieved by substituting field labor, especially work performed from the outside of a building facade using exterior scaffold means, with mass production and shop labor performed in appropriate working environments having better quality control, material handling means, automation and machinery. Method of attaching panels to mullions of preferred embodiments of this invention are performed from inside the building preferably without any need for access to the joints from the outside.
Wind velocity increases with increased height above grade. Joints at the exterior surfaces of tall buildings should be designed to resist air and water infiltration in rain storms of high wind and water pressure.
Exemplary embodiments relate to fire resistant stopless glazing fenestration for use in buildings and other structures, to fire resistant fenestration capable of withstanding seismic loadings, machinery for providing and a method of manufacturing panels, especially glass panels, and their attachment to mullions.
Fenestration includes windows, multiple window strips, curtain walls, store fronts, entrances, sloped glazing and the like. Fenestration includes a frame of at least one piece, which holds at least one panel, or a supporting grid frame having multiple vertical and horizontal members to hold multiple panels. The frames and panels can have an endless variety of shapes, forms and sizes. Panels may be made of glass, metal, marble, granite, composite or the like. Some types of glass and other facing panels can be provided in a fire resistant rated panel. Frames for use in curtain walls are made of metal, plastic or wood, but the currently aluminum available frames do not have any fire resistance for use in fenestration and curtain walls.
Facing panels are structurally secured to a mullion grid system, which is and attached to a structure or a building. The grid is pre-fabricated, shipped and installed in modular unitized units comprising single or multiple panels, where the size of a modular unit is decided by shipping and site erection capabilities. Units are installed or constructed on a building façade piece by piece and meet at a construction joint. The construction joint has a special split mullion composed of two mullion halves with each such half comprising the parameter grid member of a modular unit. The joint between the two halves of the split mullion at the construction joint is preferably adapted to allow for fabrication tolerances between components, and to perform as an expansion joint to allow for the movement caused by differential thermal expansion between adjacent multiple modular grid units in relation to the structure behind mullions, between the mullion grid and the panels, and between adjacent panels.
Mullions that occur at a central area between parameter mullions of a modular unit are preferably made of a one piece mullion. In the case of a façade being designed with end walls built from different materials, exposed at the outside and abutting a parameter mullion of such a modular unit, the mullions abutting the parameter built end walls are made of a one piece mullion or preferably similar to mullion halves. Furthermore, for seismic safety considerations, unitized mullions are preferably made of two symmetrically shaped non-interlocking mullion halves adapted to withstand earthquakes. Alternative embodiments can be adapted such that their assemblies are fire resistant. Horizontal mullions not shown are similar to preferred embodiments shown herein for a vertical mullion and may accommodate mechanical means to support the weight of facing panels.
Fire in a multiple story building can be devastating. Fenestration, and in particular curtain walls, do not resist or contain fire. Rather, the fenestration is usually destroyed by fire, and flames can spread from one floor to an adjacent upper floor, from the outside of the building through the destroyed exterior skin of the curtain wall or other fenestration. Therefore, fenestration is destroyed by the fire on the floor where the fire originated and usually destroys the fenestration directly above that floor and spreads to the adjacent upper floor, and so on throughout the building.
Advances in resin composite materials technology have resulted in a new light-weight, high strength material with unique fire resistant properties. Materials such as Moldite™, manufactured by Moldite Technologies of Novi, Mich. are one such product.
U.S. Pat. Nos. 5,381,637; 5,355,654; 6,857,233 and 5,579,616 describe curtain wall systems and panel securing systems for creating the exterior surface of a multiple story building. The disclosures of the above-identified patents are herein incorporated by reference.